| 摘要 |
<p>In an automatic gain control (AGC) network in a video signal processing system, a comparator (70) responds to an input control signal for providing an output control signal to an RF tuner (23) amplifier for decreasing its gain below a normal maximum level when the input signal exceeds a threshold value. The operation of the comparator is inhibited beyond a predetermined level of the input control signal, to prevent a false output gain control signal from being developed. The input control signal is applied to the comparator (70) through transistor (84). As the input control signal falls beyond the predetermined level, the comparator (70) input is prevented from falling by inhibiting clamp transistor (90).</p> |
